Internal-combustion engine of the two-stroke type



C. E. HEIBIG Abril 29, 1930.

INTERNAL COMBUSTION ENGINE OF THE TWO-STROKE TYPE Filed Aug. 4f 1928 April 29, 1930- c. E. HEIBIG 1,756,354

INTERNAL COMBUSTION ENGINE 0F THE Two-STROKE TYPE Filed Aug. 24, 1928 2 Sheets-Sheet 2 4/ I @fry Vic ' Patented Apr. 29, 1930 Y Y0F MENNECY, FRANCE AppiicauonmeaAugierai,1e2s,isefi`a1 fno.

, Engines.ofthetwofstrole type are already knownin which-the gas supply Vpump is disposed inthe 'power cylinder. Suchi 4appa-y ratus comprise cylinders lhaving differentv boresv coacting rwith respective? parts of af given, piston having .the corresponding diameters, said piston being connectedwiththeA Apis'tonrod. `-In'this mannerthe gassu'pply Y pump consists ofthe'large diameter part of the piston coacting with the corresponding bore ofthe cylinder."4

The present inventionv relates-to van engine ofthe two-stroke type in which thegas supply pump is disposed in the.l power cylinder, but on the contrary to the-known de vices1 the cylinderv bore is uniform throughout its entirev length.'VV Inthis case vthe preycompression of the fuel gas mixture is'obtained by therelative'displacements vin the cylinder7 of a piston whichis controlled by the piston rod and which controls the admission ports7 "andalso of a second piston which is connected with the irst by an elas- Vtic device and which is provided with an automatic valve connecting the explosion chamber with the chamber of variable volume comprised between the said pistons.

In the appended drawings and by way of example: f y

Figs. 1,` 2 and 8 show respectively accord- Y ing to two vertical sections in ther90o relaytion and in various positions, the essential parts of an engine constructed according to the characteristics'of the invention. Y

- 1 Figs. 4 Vand 5 relate to modifications which" are in section. f

According to the invention, v'the piston which is movable in the cylinder l, is made in two parts which are movable with refer- 40 ence to one another in 'such manner as to' form between thema compression chamber l2 of variable capacity. One of the said parts 3 is mounted in the known manner upon the pin 4 of the end of the piston rod. 'The otherpart 5 also forms a piston and constitutes the movable wall of the explosion chamber 6.' The said part 5 is provided with an automatic vvalve? connecting the exploablev volume which is formed between the 5,y andfurge's them apart.

Y the Part 3 0f theV piston uncovers Vthe admis- "si'onfports l0. f q n sion chamber 6 with the chamber 2 of vari- -fthis permits the part 5 ofthe piston *to v100 301,570, ana in'eeimany August 431, 1927. 'i l parts '3 and 5 in virtue Vof their relz'ttivedis placements. 1 A spring 8 of determined tenvsion"'connects together thelmembers 3 and The` explosion l chamber. 6 comprises a :poppet valve 9l (vor a valve' sleeve as'shown in rig.` 5) whih issuimbiy ontroned. The cylinder "1' alsocomprises the v"admission ports 10 controlledby the displacement of thepart 3 as well as anequrpressuregroove ll. whose :00-

The operationis as follows:

. Liet it supposed that ythe piston rod head is'atthje 'upper deadicentre," and that v the ex plosion'has just taken place (Fig. l.) f 6l?- The two parts l3450i the piston are also :fat lthe upper dead centre inthe cylinderY 1.

' The saidparts '3 5' have the minimum distance apart7V andhence the chamber ormed between th'e two has the minimum volumefqo ,Thejspring 8 connecting the two parts is at its Vmaximum compression. The automaticV "valve 7 Vis obviously pressedupon its seatjby thepressure of thev gas which now begins to expand. `The whole combination descends( 7 5 1n the cylinderuntil the piston lrod* head attains the positionOFi--OAL'A Atfthifs time the 'exhaust'valve 9 opens; and f A so The 'reduction of the pressure which is exercised upon the pistonv 5l andv which ,fref sults from the exhaustistroke, permitsl the expansion ofthe elastic device *8, so. that thel distance between the parts 3iand15 williiS5 K increase,- the part 5 continuing to descend.

The,volume of the intermediate'chambenQ l increases, and the resulting vacuum produces the* suction .of the combustible mixture `thrOllgh the-'Ports'rjloi FigtQ shows-therela-"GO' Y tive positions Aoi the severalparts of the-engine at thetime iat-which the piston rod head has cleared'thef lower deadfcentre and the part 3Y of Vthe piston has commenced .toA V y' rise. y V95A The said part 3 closes the ports 10 and shuts oli the gas admission when the piston rod head attains the point F'. A. Shortly arterv (posi.l

tion FE) thef'exhaust va1ve'9 is closed, and

i -bustion chamber 6 (Fig. 3).

make contact with the lower part of the com` The said part 5 is thus held in the fixed position, while the other part 3 moves towards the upper dead centre. The part 3 acts as a piston which compresses the" gas mixture and also the spring 8. When the compression attains a vgivenvalue, the automatic valve 'Z opens; the

.pressure contained in the space 2 between the .parts 3 and -5 of the piston.- V

This expansion prevents the discharge of V .said gas Vinto the main admission conduit '25' when the movable part 3 uncovers the parts "10. From al constructional standpoint, the

parts 3 and`5` areprovided with the annular grooves 12 and 13 bywhich the corresponding ends of the springS may be secured. .In Ithe .part 3 is ormedfan i.axial chamber 14 which is adapted to receive the rear end, and

' also thewsp'ring, of the automatic valve. 7, whose seatmay be placed `upon 'the Vpart Y5.

'l -LAfn interna-lcombustion engine of the l two 'stroke type, includingacylinder, 'alower ffii-.piston reciprocating therein, anupper -psv Y Onthe outer end of ythe said part 5 is vformed'the annular flange 15,\and at Vthe end of the stroke thesaid -langeengages a corresponding groove 16 in the cylinder head. .The whole device thus forms V'a cushion arrangement, .due .to the compression of the gas which takes place between the said parts. This disposition obviates the .mechanical shocks at the end of the stroke. For a like purpose, Vthe lower part 3 carries at the top an extension 17 coacting with the other part ton reciprocating in said cylinder, resilient connecting means between thepistons, an upper exhaust port, and a lower admission port, the said cylinder having an expansion groove formed therein to allow the gas between the two pistons to expand during the power stroke.

3. An internal combustion engine of the two stroke type, including a cylinder, a lower piston reciprocating therein an upper pistonY reciprocating in said cylinder, resilient connecting meansbetween the pistons, an upper exhaust port, a lower admission port, the said cylinder having an expansion groove 'formed thereinto allow the gas' between the two `pistons to expand during the power stroke, and a stop limiting the upward move ment of the upper piston,

4:. An internal combustion engine of the two stroke type, including a cylinder, a lower .1.

piston reciprocating therein, an upper piston reciprocating 1n said cylinder, resilient connecting means between the pistons, an upper exhaust port, 'a lower admission port, the

Vsaid cylinder having an 'expansion groove formed therein to allow the gas between the two pistons to Vexpand during the power stroke, a stop limiting the upward movement eff the upper piston, and means carried by the opposing faces of the pistons to provide Aavcushion eect between them.

,In testimony whereof I aflix my signature.

`crninifas nMiLn nanars.

of the piston 5. The annular flanges 19 exy, Vtending from .the respective parts 3 and 5 may even be employed (Fig. and said anges willrshut off .a gas cushion coacting with the 'face off the other part ofthe 'piston for dampingpurposes. The spring 8 may be dispensed with in the Acaseof engines of the ro- :farytype I claim:

l. An internal combustion engine of the y two Vstroke type, including a cylinder, a lower plston reciprocating therein, an upper piston reciprocating. in said cylinder, yresil-V ient connecting means between the pistons.

vantipper exhaust iport, a lower admission port, and means providing for the expansion V#of Ythe 4gas between :the pistons during the ypower stroke. 

